1896.] 245 [Smith. 



tion 10, southeast quarter of northwest quarter, were found specimens 

 oi Macro don too poorly preserved to be identified witlx any species. 



Genus Nucula, Lamarclv. Nucula parra McCliesney, Proc. Chicago 

 Ac. Sc , i, 11. 39, PI. ii, Fig. 8. Nuciila parva McChesney, Meek 

 and Worthen, Geol. Sitrv. Illmois, v, p. 589. 

 This diminutive Nucula, which is found in tlie Coal Measures of Illi- 

 nois, was found in the form of casts in ferruginous shale of the Lower 

 Coal Measures of Conway county, 5 N., 16 W., section 17, centre of the 

 north half, and in similar strata of the Upper Coal Measures in Craw- 

 ford county, 10 N"., 30 W., section 10, northwest quarter. 



Nucula veiitru'osa Hall, Geol. Surcei/ loica, Vol. i. Part ii, p. 71(5, PI. 29, 

 Figs. 4 and 5. 



This species is common in both Lower and Upper Coal Measures from 

 Pennsylvania to Texas. In Arkansas it was found in the Lower Coal 

 Measures in Conway county, 5 N., 16 W., section 17, northwest quarter, 

 about four miles southeast of Morrillton. 



Genus Nuculaxa, Link. Nuculana aff. helUstriata Stevens, 



This specimen, found in the form of a mould, showing very distinctly 

 the hinge teeth and the surface markings, resembles in general form 

 Nuculana belUsti-iata Stevens, Am. Joui'n. 8c. , 1858, Vol. xxv, p. 261, but 

 differs from it in having the concentric ribs much coarser and less 

 numerous. 



Locality, Scott county, 1 N., 28 W., section 4, southeast (piarter of 

 southeast quarter, in the L'pper Coal Measures. 



Genus Schizodus, King. Schizodus cuneatus Meek, PI. xxii. Fig. 3. 

 ScMzodus cuneatus Meek, Pal. Ohio, Vol. ii, p. 336, PL xx. Fig. 7. 



An internal cast from the L^pper Coal Measures of Crawford county, 

 10 N., 30 W., section 10, southeast quarter of northwest quarter, agrees 

 in shape with the species described by Meek from the Lower Coal 

 Measures of Ohio. The strongly elevated beak without any backward 

 curve is very characteristic. It being an internal cast, the obscure lines 

 of growth seen on the specimens from Ohio do not show, but the muscle 

 scar is distinct, and indications of tlie hinge teeth can also be seen. In 

 Paleontolofjy of Ohio, Vol, ii, p. 337, Meek mentions a similar ScMzodus 

 from the Upper Coal Measures of Nebraska, but thinks it is probably a 

 distinct species, on account of the small size, more nearly central beaks 

 and more prominent central and anterior margins. The specimen from 

 Arkansas really agrees better with this description than it does with the 

 undoubted ScJiizodus cuneatus, but the Nebraska specimen was never 

 figured and named. Schizodus cuneatus was also found in the Lower 

 Coal Measures of Conway county. 8 N., 17 W.. section 33. northeast 

 quarter of northeast quarter. « 



